It is recommended that you complete the
getting started guide prior to
reading this section of the documentation. The getting started guide will
explain all the basics of writing and testing policies. This section of the
documentation will serve as more of a reference guide to all available
features of Sentinel.

Sentinel provides a language and workflow for building policy across
any system that embeds Sentinel. By learning Sentinel once, you are able
to effectively control access to many systems using Sentinel's powerful
features.
Sentinel also provides a local CLI called the
Sentinel Simulator for developing and testing
Sentinel policies. This CLI can be integrated into a daily developer's
workflow along with CI to treat policy as code.

Sentinel uses its own language for writing
policies. You can view a language reference
as well as the specification for details. You
don't have to read those documents immediately, since the language should
be easy enough to pick up throughout this section.